JSON Formatter & Validator
Format, validate and pretty-print JSON in your browser. Pick an indent, paste your JSON, and see errors highlighted. No uploads.
100% in your browser — files never uploaded.
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How to use the JSON Formatter & Validator
- 1Paste JSONAny JSON — objects, arrays, numbers, nested.
- 2Pick indent2 or 4 spaces (or none, for compact output).
- 3CopyClick Copy or select the formatted output.
What does JSON formatting do?
JSON formatting normalises whitespace and indentation so a compact `{"a":1,"b":2}` becomes a readable multi-line tree. The semantic content stays identical; only the formatting changes.
Validation parses the input. Any syntax error (trailing comma, missing quote, mismatched bracket) is surfaced with the parser's message.
Frequently asked questions
Free?
Yes — no signup.
Are inputs uploaded?
No, everything runs in your browser.
Does it minify?
Set indent to 0 for compact output.
JSON5 or JSONC?
Strict JSON only — no comments or unquoted keys.
Mobile?
Yes.
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